Conference Agenda

Wastewater-Based Epidemiology (WBE) has been adopted as a low-cost, unbiased method of monitoring the spread of COVID-19. Viral signals can precede clinical testing by several days, making it an appealing basis for developing decision-support tools for public health interventions. However, WBE signals are subject to in-sewer processes that complicate their interpretation. Moreover, sewer dynamics vary between sewersheds, making the joint interpretation of WBE data between cities challenging. Wastewater quality data have been shown to help normalise WBE; however, it is unclear which wastewater characteristic can best perform this task. This study investigates the applicability of convolutional

neural networks for developing short-term (7-day) forecasting models for public health indicators

based on a WBE signal and wastewater quality data. A novel model structure is proposed

to create a city-agnostic model that can be easily applied to new cities after it has been trained. The

proposed model is tested on field data from 9 mid-sized North American cities. The model structure is

found to perform better than simple models, warranting further investigation. Analysis of the model

performance indicates that WBE signals support the prediction of new cases and that providing

wastewater characteristics allows the model to better generalize its learning to new sewersheds.

Urban drainage transports chemical, pathogens, and PM constituents; impacting aqueous chemistry acutely and chronically with consequences to human and ecological health. As a unit operation and process, clarification basins that treat urban drainage, now exceeds 10 million and intercept approximately 25% of the runoff in the USA. Design and regulatory guidance of clarifiers employs presumptive guidance based on mean residence time (RT). Decades of such guidance have led to an impairment designation for most urban clarification basins. A coupled CFD-ML model is presented herein. The databases are generated from CFD simulations for 160,000 combinations of geometric configurations, PM granulometry, partitioning and physical modeling data. Optimized results are based on the CFD-ML model, compared to RT-based models and the CFD-ML results are benchmarked with monitoring data and clarifier retrofit/land costs. Results, benchmarked with monitoring and cost data for full-scale operational clarifiers, demonstrate that optimization provides cost reduction of at least 10X compared to RT requirements at a given level of treatment.

Within the presented study 3D numerical model runs of grate inlets with supercritical surface flow conditions are done with the aim of expanding the knowledge of the street grate inlet capacity and the flow conditions that occur. Information of interaction processes from street to sewer are necessary to build up 1D/2D dual drainage models in order to get realistic information about urban flooding in case of intense rainfall events. Validation of the 3D model is done by use of laboratory results. The surface flow approaching the grate inlet with high flow velocities and small water depths can be simulated with good accordance to the measured results from laboratory. Major deviations occur in the intercepted flow rate and the water flowing over the grate. The analysis of the results allows the assumption that the deviations are probably caused by an insufficient calculation geometry.

This research investigates the potential for enhancing urban energy efficiencydecarbonisation through wastewater heat recovery systems, focusing on heat recovery techniques, theiroptimisation and integration into urban infrastructure. Wastewater, as a continuous energy source, offers a stable source for heat recovery with minimal environmental impact. The research demonstrates the optimised recovery of heat from a sewer network with 41 pipes, the application of genetic algorithms for system configuration, and the optimal locations for installing heat exchangers.

Due to increased noticeable effects of climate change, coastal cities are urged to simultaneously protect against rising sea levels and maintain, and enhance, well-functioning stormwater drainage systems. Given the significant uncertainties associated with future projections, this work aims to evaluate the sensitivity of the drainage system to selected future scenarios. To achieve this, a total of 27 projected scenarios were generated for three time-horizons, combining sea level rise and rainfall in one-year long time series using openly available data from the Swedish Meteorological and Hydrological Institute (SMHI). These scenarios were tested using a hydrodynamic 1D model of the pipe system in Landskrona, Sweden.

The results indicate that the system performs well up until 2070 across all investigated scenarios. By 2100, however, performance indicators reveal the crossing of a threshold, resulting in greater variability between scenarios and a decline compared to earlier levels. Further analysis will focus on determining the exact threshold level and identifying the key contributing parameters. Additionally, more performance indicators will be incorporated, and the results will be analysed geographically to provide enhanced guidance for urban planners.

Stormwater is a known source of faecal contamination of receiving waters in urbanised areas. WSUD systems are proposed as a promising way of decreasing pollution levels within the stormwater discharge. However, application of these systems at the real estuarine scale can be costly and the effects on the receiving waters remain at best a guess. Therefore, modelling of both receiving water faecal pollution dynamics as well as the faecal pollution in the raw stormwater runoff and the selected WSUD treatment technologies for these stormwater inputs can reveal the magnitude of these effects within the receiving water environments, helping guide future mitigation strategies and investments towards the optimal solutions for improvement of microbial water quality. In this study, a combination of 3D process-based and conceptual models was applied for simulation faecal microbial dynamics in an urban estuary, stormwater inputs and biofiltration of the stormwater to assess the effect of WSUD treatment on over 200 stormwater drains discharging directly into an estuary. WSUD treatment of stormwater inputs showed potential but limited effects on the overall microbial water quality, which was related to the magnitude of stormwater inputs in comparisons with other faecal contamination inputs in the estuary.